Specifying MVHR for Your Next Project
For architects, engineers and designers, a successful MVHR installation starts long before ductwork reaches site, when the design team coordinates ventilation strategy, plant space, duct routes and terminals with the building fabric, rather than fixing them afterwards. This matters most in low-energy Irish homes, where performance depends on correct sizing, practical routes and commissioning against the finished installation.
ProAir supports project teams from initial design through supply, installation and commissioning, ideally brought in early to protect ceiling zones, service voids and plant space while decisions are still open. A site survey is always required before installation, since site conditions and other services may differ from what’s shown on the drawings.
What does specifying MVHR actually involve?
MVHR specification is the process of defining how continuous whole-dwelling ventilation will be delivered, controlled and verified for a particular building. It covers more than selecting a heat recovery unit: it connects regulatory airflow requirements with the real layout, occupancy and construction sequence of the project.
At design stage, that normally means establishing the required airflow rates; identifying supply and extract rooms; selecting a suitable unit; reserving space for the unit, distribution boxes and ductwork; coordinating ingress and egress terminals; addressing noise, condensate and maintenance access.
The responsibilities can vary by project. An architect or building designer may lead spatial coordination and product selection, while an engineer or M&E consultant may own the performance specification and compliance strategy. The strongest outcome is achieved when those roles connect early with the specialist ventilation designer.
What Part F means for your ventilation spec
Part F of the Irish Building Regulations requires adequate and effective ventilation.
For an MVHR design, compliance is not demonstrated by naming a compliant product alone. The proposed system must be capable of delivering the required whole-dwelling and room extract rates, and the installed system must be commissioned so that its measured performance can be recorded. The design should therefore consider pressure losses, duct sizes and routes, terminal positions, controls, noise and access. All of these can affect the result achieved on site.
Part F should be read together with the wider project requirements and the current published guidance. The person responsible for compliance should confirm the applicable standards and transitional arrangements for the individual project.
Where NZEB requirements fit in
NZEB requirements sit primarily within Part L, but ventilation design is an important part of the overall low-energy strategy. As buildings become more airtight, they lose less air through uncontrolled leakage. That makes a designed ventilation system essential for indoor air quality and moisture control. For the full NZEB standard, see SEAI’s NZEB guidance or the Irish Green Building Council.
MVHR continuously extracts stale, moisture-laden air from wet rooms and supplies filtered fresh air to habitable “dry” rooms. The system passively transfers heat from the outgoing air to the incoming air, reducing ventilation heat loss. This supports an energy-efficient building strategy.
MVHR specification, from design to sign-off
A practical specification process should follow the project from drawings to verified performance:
- Review the project information. Confirm floor area, dwelling layout, intended occupancy, airtightness approach and anticipated level, construction type and any unusual features that may constrain the ventilation design.
- Establish the ventilation duty. Calculate the required whole-dwelling and room rates under the applicable guidance, then select equipment with appropriate capacity.
- Coordinate the layout. Identify supply rooms, extract rooms, unit position, distribution boxes, primary duct routes, ceiling or floor zones, intake and exhaust locations, condensate drainage and maintenance access.
- Develop the project design. Produce a coordinated ventilation layout and schedule that the architect, engineer, designer, builder and installer can use. Resolve conflicts with structure, steelwork, joists, services and fitted furniture before installation.
- Install and quality-check. Use the specified duct components, keep routes clean and sealed, and protect the design intent as site conditions change.
- Commission and hand over. Balance the system to the required room rates, record the results, set up controls and explain filter changes, boost operation and routine care to the building owner.
Selecting the unit: performance and installation suitability
ProAir’s Irish-made PA700LI serves homes up to approximately 270 m², subject to the calculated airflow and system resistance. Its published data lists a maximum airflow of 550 m³/h at 100 Pa, heat-recovery efficiency up to 95%, an A+ SEC rating, integrated temperature, humidity and CO₂ sensing, and summer bypass as standard.
Never select a unit on floor area alone. A long or complex building, restrictive routes or a high room count may require a different arrangement even where the nominal area appears suitable.
Why architects, engineers and designers specify ProAir
A useful MVHR trade partner brings technical continuity to the job. ProAir designs and manufactures its systems in Galway and provides nationwide support through its Irish offices and installation network. ProAir lists its products on the PCDB. The PA700LI also has published performance data that can be reviewed at the specification stage. Independent ITS2 testing confirms best-in-class heat exchange efficiency for the PA700LI.
For the design team, the value is practical: one specialist partner can help translate the performance requirement into a buildable solution, coordinate the layout with the project team, support installation and complete commissioning. That reduces the gap between what appears on the drawings and what must work in the finished building.
ProAir can work with architects, engineers, M&E consultants and designers on one-off homes and larger residential projects.
What ProAir handles / What your team handles
| ProAir Can Support | Your team typically handles |
|---|---|
| Review of relevant plans and project information | Providing up-to-date architectural drawings, sections and elevations |
| Ventilation airflow calculations and system selection | Overall building design, structural coordination and airtightness strategy |
| Confirmation of the regulatory route, assigned-certifier requirements and wider compliance strategy | Sign-off on compliance strategy with the assigned certifier |
| MVHR layout, unit location and duct-route input | Coordinating MVHR routes with structural, electrical and other M&E services |
| Supply and, where agreed, installation of the MVHR system | Site access, programme scheduling and coordination with other trades |
| Balancing, commissioning information and user handover | Passing handover information to the building owner or occupier |
Frequently Asked Questions
Does ProAir provide CAD drawings for specification?
ProAir provides project-specific ventilation design information and detailed drawings for the agreed scope.
Is the PA700LI suitable for commercial and multi-unit specification?
It may be suitable for some applications, but it should not be specified by building type alone. The PA700LI is published for larger homes up to approximately 270 m² and 550 m³/h at 100 Pa. Commercial or multi-unit proposals require project-specific assessment of airflow, zoning, occupancy, fire strategy, acoustics, controls and the applicable regulations.
How long do design and commissioning typically take?
The programme depends on project size, drawing quality, coordination requirements and site readiness. ProAir can confirm a realistic design lead time when the current plans and project requirements are received, and commissioning can be scheduled once the installation is complete, powered and ready for balancing.
Can ProAir support NZEB compliance documentation?
ProAir can provide technical specification information and performance data to support the wider NZEB compliance strategy. Confirmation against SEAI or IGBC guidance, and sign-off on compliance documentation itself, remains the responsibility of the project’s assigned certifier.
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